Abstract

The paper presents the design and operating characteristics of a model of eversible axial fan with only one impeller, whose reversibility is achieved by hanging the direction of rotation. The fan is designed for the purpose of roviding alternating air circulation in wood dryers in order to reduce the onsumption of electricity for the fan and increase energy efficiency of the entire ryer. To satisfy the reversibility of flow, the shape of the blade profile is ymmetrical along the longitudinal and transversal axes of the profile. The fan is esigned with equal specific work of all elementary stages, using the method of ift forces. The impeller blades have straight mean line profiles. The shape of the lade profile was adopted after the numerical simulations were carried out and igh efficiency was achieved. Based on the calculation and conducted numerical imulations, a physical model of the fan was created and tested on a standard test ig, with air loading at the suction side of the fan. The operating characteristics re shown for different blade angles. The obtained maximum efficiency was round 0.65, which represents a rather high value for axial fans with straight rofile blades.